A projector that projects an image based on image data that is input is known.
An educational field, for example, is a big projector market, and the number of cases where a projector projects an image on a blackboard or an electronic blackboard in a school or the like may increase.
A method of inverting between the white color and the black color in a photographed image based on a histogram of pixel values of the photographed image to project, for example, is known for improving the visibility when the photographed image is projected directly on a blackboard. Actually, first, based on the histogram, it is determined whether the white color and colors close to the white color are more than the black color and colors close to the black color throughout the photographed image. If it has been determined that the black color and colors close to the black color are more than the white color and colors close to the white color, the black and white inversion is carried out on the photographed image (see PTL 1).